Permafrost
by Darthkvzn
Summary: The history of Asgard and Earth has always been murky. They've never thought much of us, and we don't exactly believe in them anymore. The Thunderer's arrival changed that, but he was not the only Asgardian to visit... Part of my Marvel Universe. Rated T for mild adult situations and language. Canon pairings.
1. Chapter 1

**I watched Frozen. I love Elsa - and I adore the Avengers with a passion. This is my best attempt at uniting the two. I hope you enjoy!**

* * *

 _991 A.D., the outskirts of T_ _ønsberg, Norway._

A generation had passed since the Jotünn had invaded, and the place was still bloody cold.

-"Father, when will the gods come? I want to see the Rainbow Bridge!" -asked Lene, daughter of Arnbjörn.

The man in question smiled sadly. "It will not be long now, daughter. You would do best to brace, their arrival is usually quite potent." -he said.

The child gave a toothy grin, tucking herself into a mock of a fighting stance, one she'd most likely seen her father practice before.

Some time passed, with the child asking his father all sorts of inane questions, and the man indulging her with wild answers and tales to astonish. The skies turned gray, all of a sudden, and the man knew, once he saw the swirling vortex descending upon Midgard, that the two of them were about to be in the presence of their gods.

The Bifröst touched down with an enormous rumble, sending a cloud of dust and snow swirling around. A mighty neigh was heard, then, heralding the arrival of the All-Father, sat astride Sleipnir, the eight-legged horse.

Arnbjörn immediately took a fist to his chest and kneeled, beckoning for his child to do the same.

-"Rise, Arnbjörn, son of Ingvar. The All-Father would have words with thee." -said a quiet voice, that somehow managed to _sound_ powerful.

The man did as was asked, and came face to face with an enormous man, taller and stronger than any he'd ever seen. His golden war helm and armor gleamed like the morning sun, and the scepter he held thrummed with power.

-"All-Father. I have done as you asked. This is my only heir, Lene Arnbjörnsdöttir. I humbly beg of you that you might reconsider…" -he said, agitatedly.

Odin narrowed the eye not covered by his helm. "Once, you asked for my aid, and that of the warriors of Asgard. I brought the might of my armies, and the blades of my men, and many of them paid the ultimate price."

-"Yes, All-Father, but I did not think…"

The Aesir looked at the mortal king in contempt. "You mortals rarely do. When I answered your call, I warned you fairly - I would take something of yours, when the time came. You eagerly accepted my terms. I would have your daughter."

The man's expression looked incredibly downcast, and Odin's own expression softened. "However, I am not without pity or compassion. As you are well aware, that makes for a poor ruler. I will not keep your daughter from you. But her and her line will bear a curse that will eventually turn to blessing - one that may very well save your Realm and the other Eight from doom one day."

Arnbjörn looked lost, perhaps in regret of the rash, yet necessary promise he'd made to the god when his father's kingdom had been besieged by the Jotünn. "I'll do it, my lord." -said his girl, surprising both elders.

Odin kneeled, barely able to look the wee lass in the eye. "You would sacrifice yourself for your kingdom and your world?"

-"Aye." -said the girl, defiantly.

The All-Father picked her up, chuckling. "This one would make a fine playmate for Thor. You are very brave, lassie. I have little doubt that your name will join the ones chanted in the Mead Halls of Asgard, for all eternity."

The girl looked awestruck as the god set him down. Odin then picked up Gungnir, the badge of his office, and tapped the child in the chest with the tip of the spear. The divine metal stuck to the girl's skin, who began to shout, confused and in pain, as a symbol branded itself into her chest - an intricate snowflake, dark blue in color, no bigger than the child's hand.

King Arnbjörn looked away, willing himself not to immediately pounce on the god hurting his girl. Odin chanted away in some strange, unknown language, and the staff became charged with blue energy, and covered in frost. The calm weather around them turned to a blizzard, and the man's teeth chattered as the temperature dropped such that his breath froze in midair.

Lene's skin turned blue, runes and lines appearing on her skin, her eyes turning red and her teeth becoming crooked and wild. And then, as suddenly as the All-Father had started the process, everything returned to normality. The girl looked as she had before, and the weather returned to normal. The only evidence that anything had happened was the symbol on the child's chest, and the tired figure of Odin, whose power had apparently been spent.

-"Go now, King Arnbjörn. Enjoy your daughter, cherish the time you have. I will tend to my family as well. But do not forget: this curse was brought to your daughter by your hand."

King Arnbjörn would remember these words last, on his deathbed. He would eventually pass on to Valhalla, though not before sharing a tearful good-bye with his beloved daughter. In the years after the encounter with the god, he'd wonder - just what curse had he placed upon his family's future?

* * *

 **This is purely setup. Just what did Odin do? Ask away and ye shall receive an answer! Until next time - Darthkvzn**


	2. Chapter 2

**Oh hey! I kind of uhhh forgot to write for this story. Too many projects at once, I don't recommend it. Anyway, give it a chance!**

* * *

 _Arendelle Glacier, 28th of December, 1999_

Working on Christmas week definitely sucked. Even more so, considering Senior Agent of S.H.I.E.L.D. Maria Hill was currently stuck overseeing yet _another_ recovery operation for Captain America's body, smack-dab in The Middle of Nowhere, Norway.

It's not like she had anyone waiting at home, but sometimes, she wished she had a job that respected holidays.

Hill's radio chimed. " _Agent Hill, come in._ "

She sighed. "Hill here. What do you have for me Sitwell?"

-" _Cold spot. Some energy signals along the lines of the Cube's._ "

An eyebrow went up. "On my way. Don't let the eggheads touch anything yet."

Her S.O., Nick Fury, had recently been appointed Director, following former Director Carter's resignation due to illness. Fury's first act as head of S.H.I.E.L.D. had been to update the Index - the agency's growing list of enhanced humans to keep an eye on. He'd also kick-started some research into safe human enhancement, which meant finding Captain America's remains had become a higher priority than just the late Howard Stark's obsession-slash-pet project.

Hill walked up to the excavation site, calling up the elevator and rubbing her hands for warmth. 50 feet later, she was approached by Jasper Sitwell, her immediate subordinate. Sitwell was a fairly capable agent, though not one she fully trusted. Hill wasn't a people person on the best of days, but there was something about Sitwell that had never sat well with her.

The man handed her some papers. "Trace gamma radiation and an abnormally cold spot, approaching absolute zero. The temperature drop wasn't in Stark's notes, but..."

-"The Tesseract was an extremely adaptable energy source. It's possible it left its mark this way, I get it. Where are we on digging whatever it is out?" -she asked, flipping through the pages.

-"Five minutes, tops. The tools keep breaking."

Hill suppressed the urge to snort. "Let's get back, then."

As soon as the workers gave the ok, a containment team in heavy winter combat gear approached the singularity. The automated mining equipment broke through the last layer encasing the object, which unleashed a particularly powerful gust of wind. Hill thought she saw snowflakes in it, but it must've been a trick of the light.

-" _All clear, ma'am. You're gonna want to see this."_ -came the voice of the containment team leader, Larry White.

Now, Hill knew White to be a serious man, rarely fazed by the weird things he was often sent in to, well, contain. For him to be surprised by the find, meant this little excursion might not have been _quite_ as worthless as she'd have originally thought.

Hill approached the scene, donning extra heavy winter gear. Exactly in the middle of the ice structure was a disturbing figure. Hill would've thought it a particularly morbid statue, if not for the fact that the partially corroded bones were clearly real.

A frost covered skeleton held a broken sword, thrust into a statue of a young woman made from the purest ice Hill had ever seen. Jagged ice crystals spread from the 'wound', as if they had exploded. Ice wasn't normally seen as dangerous, but Hill knew just how dangerous it could be from survival training. Ice crystals were incredibly corrosive, and whoever had been unlucky enough to unleash these had quickly been destroyed by them. Some of the bones were even broken.

Hill crept closer. Now that she was closer, she could see that the ice sculpture gave a sort of glow, not reflected but rather originating from its core, where the sword was located. The woman's sculpture itself was extremely beautiful, though her expression left a lot to be desired. She looked to be in extreme pain and anguish.

-"Techs have confirmed the cold spot is coming from the statue. They're not sure yet, but they think it might actually be keeping the glacier frozen. The region has been melting steadily, but this one has kept pretty much the same." -said Sitwell, his expression somewhat fearful.

Hill thought this over. "Have a team dig out the skeleton and the statue but keep the sword where it is. I have a bad feeling about this place. Make sure everyone's ready to move out as soon as we remove these two."

Nodding, Sitwell went off to relay her orders. White walked over to her, assault rifle still held warily towards the disturbing scene. "What do you reckon, ma'am?"

Agent Hill pursed her lips. "I'm not sure. Doesn't seem alien, but experience tells me not to trust that particular gut feeling."

-"Roswell, you mean."

The woman nodded. "You were there, right?"

White nodded too. "Fresh off the Academy, too. Hell of a way to start my career, that thing. Bigger, tougher, and meaner lookin', but still just a blue man. Makes you wonder what _else_ is out there."

Hill gave the old man a small smile. "Let's worry about getting out what we've got here, first."

The man gave her a hearty laugh. "All due respect, ma'am, if it's not shooting at us, that ain't my job."

She allowed herself a quiet laugh.

* * *

She'd be proven right - the glacier immediately started deteriorating when the glowing ice sculpture was removed. It happened at an alarming rate, too. Not half an hour had passed and the Arendelle Glacier split in two, with smaller chunks constantly breaking off from the edges.

Back at the Triskelion, Director Fury was expecting her.

-"Agent Hill." -he greeted her in the usual laconic manner. The older man was looking over some files, presumably regarding Hill's latest find.

-"Director. Norway isn't too happy with S.H.I.E.L.D. breaking part of the ice, but we managed to convince them there was something dangerous that needed to be removed in the glacier."

The Director nodded. "A good lie, especially since it's rooted in truth. What's your take?"

She hummed in agreement. "We still haven't removed the sword, but the skeleton proved very interesting. Carbon dating puts him at around 200 years old, give or take half a century. There's no certain way to tell cause of death with nothing but bones, but we're pretty sure the ice killed him. The cloth was fancy by their time standards, so we're thinking he was a noble."

-"I can see that in the report, Hill. I want _your_ take. What does this scene look like to you?" -he said, giving her a meaningful look.

Hill pursed her lips. "It looks...like a murder gone _very_ wrong. The techs would scoff at me for saying so, but I think the statue is, or was, alive at some point."

Fury smirked, pointing the files at her. "Bingo. Shut them up, Hill. Have them take the sword out, they'll see."

-"That would be...highly inadvisable. We have no idea how this person would respond, assuming we're right. At best, she's going to be 200 years off her time."

Fury raised an eyebrow. "We've planned for that kind of situation, and you know it."

Hill scoffed. "With all due respect, Stark was delusional. Serum or not, Rogers is dead. And the 40s are _not_ the same as the late 1700s."

-"Your complaints have been noted. Now thaw me an Enhanced, Hill."

She bit her lip, but ultimately just sighed. "Yes, sir."

* * *

 **Hey! What do you think? Three guesses as to who the skeleton is.**


	3. Chapter 3

The first thing Elsa, Queen of Arendelle knew was pain, erupting from the small of her back, opposite her navel. She could feel the panic building, and tried to force herself to calm down. She stopped the shouts she hadn't even known were erupting out of her from the pain.

The next thing she knew was that she was surrounded by strange men in strange outfits, pointing metallic contraptions that looked oddly like muskets at her. Their grim expressions and bulky suits could only mean one thing. _Soldiers_ , she thought sourly.

There was something in their eyes, though - fear, she realized. These odd soldiers were afraid of _her_. Elsa was not fond of causing terror, but she needed to leave whatever this place was. She needed to _know_.

"Back away! I will not hesitate to wound you!" -she bluffed, summoning a frosty aura around her hands and pointing them in the soldiers' general direction.

The warriors met her shouts, angrily waving their weapons at her and shouting in a language she vaguely recognized as english. Elsa took a moment to take in her surroundings, and found herself to be horrified: she was standing in the middle of what used to be a room much like hers, completely destroyed and covered in frost. A scared looking servant was hastily being taken away by one of the soldiers, as she'd been hit by some of the wooden debris, and was bleeding from her head.

Elsa felt guilty, but the damage was done. She could not afford to be weak willed, if she wanted to find out what happened to...to Anna.

" _Get down on the ground and put your hands in the air_!" -one of the soldiers shouted. Elsa scowled. Her english was a little rusty, but if the man wanted to put her in the ground, well, she wasn't about to let that happen.

Elsa shot a blast of frost at the man's weapon, which immediately froze and caused him to drop it in pain. She had about a second to enjoy her triumph, when pain pierced the upper right side of her chest. She looked down to see her chest beginning to pour blood, and panicked, taking a hand to the wound.

The pain in the wound suddenly multiplied tenfold. She took her hand away, and was shocked to find that the wound was being sealed with ice, in much the same way her magic spread, weaving itself together and leaving a small, frozen patch behind.

The soldier who'd shot her looked terrified, but Elsa didn't much care. She raised her hand and a jagged wall of clear ice sprouted from the ground. The soldiers got over their shock and started shooting again, but the ice held, and she smirked in satisfaction, splitting the wall and pushing each section towards an individual soldier.

They didn't stand a chance. The ice trapped them against metal walls that surrounded her destroyed room. Her job done, she let the ice aura around her subside. She couldn't completely turn it off in her agitated state, but a light snow indoors wasn't much to worry about.

She turned to gather her bearings. The ice over the wound brittled and fell off, leaving behind blue skin. Elsa's eyes widened, but her skin returned to normality soon enough. Before she could ponder what that meant, though, she felt a pinprick at the back of her neck. She instantly reached for the source of the pain, but her senses dulled and her movement faltered.

Her legs gave out, and she fell hard, hitting her cheek on the floor. Sleep was beginning to overtake her.

Elsa felt furious. She needed to leave! Snow began to spiral around her into a miniature blizzard, and she felt the drowsiness slowly fade.

" _Hit her again._ " -said someone.

Two more impacts pierced the skin on her back and buttocks. Before she could feel any indignation, however, unconsciousness won out, and her world went black.

* * *

Hill watched grimly as they hauled a wounded soldier out of the room. They'd been trying to get past the language barrier and the violent attitude for the past two months, but the Ice Queen wouldn't have it. S.H.I.E.L.D. had language techs working around the clock on her responses, and psychoanalysts trying to come up with acceptable scenarios for the woman out of time, but she invariably responded with increasingly lethal ice attacks. Last week, she'd summoned a golem made from snow and ice, which had actually managed to put two agents in critical condition and wounded a dozen more before being taken down. Not from damage, but by knocking out its creator.

Fury walked up to her, and she shook her head. "I'm sorry sir, but I must insist. This woman cannot be controlled or persuaded. She burns through sedatives like she has the constitution of an elephant. We've tried everything we can think of to neutralize her powers: dehydrating the room, binding her, encasing her in a container...nothing holds her back, and we're two ice spikes from losing men."

The Director considered her words. "And you're certain?"

Hill nodded. Fury sighed. "Put her under, then. We'll try again later, when we understand her better."

"Sir, even unconscious, she radiates cold. No location would be safe for containment."

Fury raised an eyebrow. "Be creative, Hill. She's cold, so give her a cold house. Harness her powers."

Hill blinked. "The Cold Storage Facility, sir?" -she asked sarcastically.

"Yes, Hill. I want her powering The Fridge."


	4. Chapter 4

_S.H.I.E.L.D. Cold Storage Facility, "The Fridge" (Location classified), May 23rd, 2012_

Grant Ward stalked through the previously thought impregnable Fridge, frowning.

HYDRA may have destroyed S.H.I.E.L.D., and he might've had a big part in ensuring the operation's success, but he didn't exactly feel happy, considering he'd had to doom two of his former teammates to their underwater graves. They were obstacles, yes, but also friends, good people caught on the wrong side of the decades old conflict. It was a shame his directives hadn't included converting them to the HYDRA banner.

Not that he would've had much success when Captain America's number one fanboy led the team, but oh, well.

In any case, the deed was done. He was firmly HYDRA, currently under orders to plunder the Fridge. Most of the heavy machinery and powerful weapons had already been secured, but there was one he was more than a little curious about still at the site, down at the reactor level.

Kind of weird, holding a weapon next to the reactor, but hey. He didn't design the base.

The long elevator ride down only served to make him shiver. The temperature descended drastically the more he descended, to the point he actually had to rub his arms for circulation.

The reactor level was all frozen pipes and frosted stone walls. Emergency lighting was the only thing impeding total darkness, a faint red glow making everything seem twice as sinister. If he hadn't been a hardened killer, he might've fallen for the scenery, but he only had a mind for locating his objective.

When he finally exited the narrow hallway into the equally small reactor room, he frowned; it was a thick metal case about the size of a sarcophagus, frozen shut. He'd been expecting some sort of vault, and the reactor itself was conspicuously absent from the hall. The cables and pipes all emanated from the sarcophagus, making it seem as if the thing actually powered the place. A digital pad was next to the metallic object.

He walked up to it, his teeth chattering slightly. Once at the pad, he input the universal HYDRA override code, which the pad accepted. There were only two options on the display: status, and open.

The double agent chose open.

A powerful gust of freezing wind broke free when the heavy door opened, revealing...a woman. Young, pale as snow, and beautiful beyond anyone he'd ever seen, the platinum blonde, freckled girl was clothed only in a skin-tight black bodysuit, hooked up to the sarcophagus itself, pumping... _something_ , whatever it was, outward.

 _Crap_ , he thought. The Fridge's source of power wasn't a machine. It was a person, and an Enhanced one at that.

Ward hurried to close it up, the heavy titanium lid moving closely. And then, it stopped, only it wasn't closed, instead getting covered with frost, the hinges frozen in place. Ward did the only logical thing, given his training: pull out his gun, and run the hell away, preferably into cover.

He was too slow.

Snowflakes started appearing in mid air, the metal door slowly opening and pushing them around softly. The cables and IVs hooked up to the woman froze, breaking off as she stepped down slowly. Her eyes were open now, her irises glowing blue with the power of frost.

Project Centipede had cooked up some scary crap. This...was another level entirely. The Enhanced walked toward him, and for the first time in a very long while, Grant feared for his life.

He wasn't HYDRA just because, however.

Grant shot his handgun thrice at the slowly advancing figure, and his aim proved true once more. Blood spilled from the wounds, two in her chest, and another in her abdomen. The woman grunted in pain, but it did not stop her for long. The crackles and pops of ice complemented the spread of a sort of frost scab over the bullet holes, which immediately filled, the frost falling off to reveal deep blue patches of otherwise flawless skin.

The traitor kept shooting until the clip was empty, only to find the same result. Blood covered her bodysuit, and left a trail behind her with each slow step she took, but her injuries healed in seconds. Ward knew a lost cause when he saw one, and so he turned tail and ran.

Of course, the woman wasn't done with him yet.

A gust of frigid air and glowing snow ran past him, then struck the floor in front of him, a thick wall of clear ice sprouting out of nowhere, filling the archway and trapping him. Too thick to punch or kick through, Ward was left with little choice but to get rid of its source.

The former agent charged the enhanced, but the woman was unimpressed. She shot another blast of frost before him, sprouting a second wall, trapping him between two walls of ice, and another two made of concrete.

" _You have wounded me for the last time_." -she said darkly.

Grant did not recognize the language, but he knew that tone. It was a threat, and one she seemed intent to go through with.

"Listen: even if you kill me, about thirty men are between you and freedom. You heal quick, but you're not gonna make it, trust me."

The woman snorted. "Why would I trust you? You have tried to kill me." -she asked, in heavily accented english.

Ward dropped his empty gun. "What would _you_ have done if someone came at you with ice shooting from her hands?"

"I did not just shoot. You shoot, and I shoot back. You lie." -she said, her hands tightened into fists.

The agent scowled lightly. "Just, put the ice walls down, and we'll talk, ok?"

She narrowed her eyes, but the walls remained intact. "Where is Anna?"

Ward frowned. "Who the hell is Anna?"

She growled, making a crushing gesture with her frost-wreathed hand. The walls came closer together, and Ward tried pushing them apart frantically. " _Anna_ is my sister. She was frozen, and your people, the S.H.I.E.L.D. people, took her. I want her _back_."

The traitor grit his teeth. "I don't know anything about your Anna! I'm not with S.H.I.E.L.D., not anymore!"

The woman cocked her head. "You abandoned them?"

Ward nodded nervously. "I _betrayed_ them...I'm HYDRA, I'm on your side." -he said hopefully.

She looked away for a second, and Grant Ward felt that maybe, just maybe, he'd come out of this alright.

The woman disagreed.

The walls sprouted spikes, like medieval iron maidens, and slowly ground together. Ward's eyes widened, but he did not scream. He would not give his killer that pleasure. The woman did not, in truth, care. Elsa of Arendelle did not care about much anymore. Only Anna mattered, and she _would_ find her, no matter how many traitors and murderers the world threw at her.

As the Ice Queen walked past the frozen, pierced body of the traitorous Grant Ward, she covered her body in icy armor. He _did_ , after all, mention there were more of his kind around...

* * *

 **I'm not sure what kind of story you guys expected, but this is the one you get! Dark Elsa's not just an excuse for me to murder one of my least favorite characters in the MCU, she's meant to be a villain with a heart of gold. She _loves_ her sister, more than anything or anyone else in the world, and she would do whatever it takes to get her back. Let's hope the Avengers are prepared...until next chapter!**


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